1. Field of the Invention
The present invention generally relates to a chuck adapter for a turning machine, and more particularly to an adjustable chuck adapter for retaining the soft jaws of a turning machine three jaw chuck in position for subsequent machining the inner diameter or outer diameter of the soft jaws to a proper size for supporting a workpiece.
2. Related Art
C.N.C. turning machines utilize chucks to hold a workpiece in position for machining. Typical of such chucks is a three-jaw chuck, each jaw having a master jaw and soft jaw component, where each soft jaw is secured on top of a master jaw of the chuck. The soft jaws must be machined to fit a workpiece to securely hold the workpiece for machining. The soft jaws are machined by rotation of the chuck mounted on the spindle of the lathe. Accordingly, the soft jaws must be secured in a proper position for machining.
Recently, Computer Numerical Controlled (C.N.C.) turning machines have come into widespread use. Such devices are extremely accurate and produce parts faster and with much better finish than was heretofore possible. The introduction of these devices caused chuck manufacturers to make chucks which require much greater holding pressure per jaw. For example, most of the power chucks available today are hydraulic or air and involve a holding pressure per jaw which could exceed 350 p.s.i. This high pressure is required to hold the parts of the jaws securely so as to withstand the high RPM of the C.N.C. turning machines in use today.
Accordingly, what is needed, and has not heretofore been provided, is a device for positioning soft jaws for machining which is simple, quick and easy to use, but is strong enough to be used with modern turning machines.
Previous efforts have arrived at different devices for locking the soft jaws in required positions for the purpose of machining the jaws to fit the workpiece at fill chuck pressure to provide to adjustment of the jaws in locking position for the exact amount of metal removal desired. These previous efforts include:
Brown, U.S. Pat. No. 4,772,034, which discloses a soft jaw construction for a lathe chuck for engagement by the studs of an adjustable lock ring device for holding the jaws during the machining thereof. The device comprises a ring arrangement to encircle the soft jaws. The ring has radially extending holes for alignment with the axis of the radial movement of the soft jaws. Studs are secured through the hole of the ring and extend into the soft jaws. Micrometer graduated nuts are utilized to limit the radial inward movement of the soft jaws to locate the soft jaws at a desired position for machining.
Mathes, U.S. Pat. No. 4,746,131, discloses an apparatus for internal chucking of a soft three-jaw chuck on lathes. The device includes two rotatable triangular clamping plates disposed in a preselected rotational position respect to each other. By rotating the triangles with respect to each other, and positioning the soft jaws along the sides of the triangle, the size of the chuck is varied based on the respective positions of the side walls so that a large number of sizes can be achieved with a single chuck.
Brown, U.S. Pat. No. 4,969,482 discloses a soft jaw construction for a lathe chuck for engagement by the studs of an adjustable lock ring device for holding the jaws during the machining thereof. The device comprises a ring arrangement to encircle the soft jaws. The ring has radially extending holes for alignment with the axis of the radial movement of the soft jaws. Studs are secured through the hole of the ring and extend into the soft jaws. Micrometer graduated nuts are utilized to limit the radial inward movement of the soft jaws to locate the soft jaws at a desired position for machining.
Ferraro, U.S. Pat. No. 4,556,228, discloses a jaw locking mechanism comprising slots extending across the bottom of the soft jaws which accept members which have lock down means associated therewith. Accordingly, the soft jaws are positioned and then locked down into position by actuating leg members which frictionally engage the chuck base.
Ferguson, U.S. Pat. No. 4,277,073, discloses a soft chuck jaw comprising a hardened jaw body having a wedge locking means thereon and an insert of soft expendable material retained therein. By utilizing a hardened jaw body having a wedge locking means thereon, the insert, which is expendable, may be formed from cold formed stock material which has the required surface accuracy, thus merely requiring the cold formed stock material to be cut to the desired length and be square on one cut edge.
Righi, U.S. Pat. No. 4,223,898, discloses a retainer device for chuck jaws having a carrier ring with a plurality of blocking slides, each slide carrying a double-hook element presenting two inwardly directed hook arms. When the retainer device is installed against chuck jaws, the double-hook element engages from both sides the steel jaw and blocks movement of the steel jaws past a desired working condition.
Thompson, U.S. Pat. No. 3,610,643, discloses a chuck adapter for locking a chuck internally into a hollow tube. The chuck adapter comprises a generally cylindrical shell having a flanged mouth and a plurality of longitudinal openings in the surface thereof. A plurality of radially movable gripping bars is pivotally or slidably mounted within the shell and has cam surfaces thereon. An axially movable member having tapered surfaces thereon is slidably mounted in the shell and the tapered surfaces are adapted to engage the cam surfaces of the bars to move the bars radially outward of the shell upon engagement of an axial end of the axially moveable member with the end of a chuck. This invention has applicability to the paper roll industry.
Lemanski, U.S. Pat. No. 3,575,435, discloses a set of attachments for the chuck of a lathe. The attachments include two forms of soft jaws that attach on a hard jaw. A set of shims is provided for gripping and positioning a ring-shaped workpiece on stepped jaws. Two forms of stops are provided for positioning the end of the workpiece in selected positions in the jaws. An adopter is provided having a friction surface and magnetic means for engaging and longitudinally supporting the end of a workpiece that cannot normally be engaged between the jaws.
Buck, U.S. Pat. No. 3,167,325, discloses a carriage fastened to the base of a chuck having radially moveable force receiving means engagable by the chuck jaws for actuation upon appropriate inward or outward movement of the jaws.
Grand, U.S. Pat. No. 3,160,042, discloses a jaw holding device comprising a rigid ring between the soft jaws which has a multiplicity of radially extending and radially adjustable projections to restrain radial movement of the jaws during rotation and turning thereof to size.
However, these previous efforts have developed generally cumbersome devices that are not quickly and easily adjustable.